Computer networks can have a large number of physical servers interconnected with one another in an underlay network by routers, switches, bridges, or other network devices via wired or wireless network links. Each physical server can host multiple virtualized servers, virtual network functions, or other suitable virtual entities interconnected with one another in one or more virtual overlay networks supported by the underlay network. The virtualized entities may be relocated or migrated from one or more originating servers to one or more target servers in the underlay network.